DIY Doctor


Postby mea » Fri Aug 27, 2010 6:35 pm

Hi, I'm after some advice. I have had my house rewired 4 years ago (it was an old house) and I knew that I was going to do work on it in the future. With this in mind, the utility room was wired to what I was going to do. I am now doing this now ( I have re-roofed, re-built etc. ) I took the electrics off the wall and now want to reinstate them exactly where they were originally - put in by the electrician. I have come up with a problem, the light was off the main circuit (with a dedicated fuse) not off the light circuit, which I believe is the norm. Was this allowed?Is it part P which is what I paid for? Also, I had an outside light and power supply on this dedicated circuit all with a fused spur for each - Is this okay? ( I wish I had taken a photos before taking everything off the walls!! :()
Thanks for any advice/ info from a very tired and confused mummy
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Fri Aug 27, 2010 6:17 pm


Simply Build It

Postby ericmark » Sat Aug 28, 2010 11:55 pm

314.1 Every installation shall be divided into circuits, as necessary, to:
(iii) take account of danger that may arise from the failure of a single circuit such as a lighting circuit.

There is nothing wrong in using a fused connection unit to connect a light but if using something on the ring which the FCU is coming was to trip the MCB which in turn plunged one into total darkness then it would of course be wrong.

Most ceiling roses are rated at 5/6 amp and as a result normally 5/6 amp it the maximum size of fuse used in a lighting circuit. However if a ceiling rose is not used as a junction box then the regulations allow 16A.

559.6.1.6 Lighting circuits incorporating B15. B22. E14. E27 or E40 lamp holders shall be protected by an over current protective device of maximum rating 16A.

So likely a fused spur is OK. But not always.

The whole idea of an installation being divided into circuits has caused many problems with the introduction of RCD protection on all circuits. Using emergency type lighting so if a fuse or MCB opens you are not plunged into darkness can often get around the problem but "(iv) reduce the possibility of unwanted tripping of RCDs due to excessive protective conductor currents produced by equipment in normal operation." sounds OK until you realise the electrician has no idea what will be plugged into a ring main so he has no idea if he will fall foul of the regulation.

As a result you have very little come back as he has a good excuse for what he has done as in many houses it will cause not problems.

I hope Sparx will add to this as he is far more knowledgeable as to customs with house electrics.
Rank: Project Manager
Posts: 2461
Joined: Fri Oct 02, 2009 8:49 pm
Location: Llanfair Caereinion, Mid Wales.

Postby sparx » Tue Aug 31, 2010 11:01 pm

Hi, pleased to be in agreement with Ericmark again.
If the work was only done 4 years ago the leckie would have to have registered it with LABC and given you test certs for it.
This being so then he has taken responsibility for the installation.
You can remove refit accessories if notaltering the circuits.
Rank: Project Manager
Posts: 2166
Joined: Wed Mar 21, 2007 8:33 pm
Location: The fifth continent.

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics